Magnetic probe device

Abstract

The present invention discloses a magnetic probe device. The magnetic probe device includes a magnetic probe body and a signal processing circuit, and an output end of the magnetic probe body is connected with an input end of the signal processing circuit; the signal processing circuit includes a first capacitor, a second capacitor, a Faraday shield and a step-up transformer, and the Faraday shield is fixedly arranged between a primary winding and a secondary winding of the step-up transformer; a center tap is arranged at the primary winding of the step-up transformer, and the center tap is grounded; and a first end of the primary winding is in series connection with the first capacitor, and a second end of the primary winding is in series connection with the second capacitor. The magnetic probe device provided by the present invention can improve the signal-to-noise ratio of a magnetic probe and the measurement accuracy of the magnetic field in plasma.

What is claimed is: 
     
       1. A magnetic probe device, comprising:
 a magnetic probe body; and 
 a signal processing circuit; 
 an output end of the magnetic probe body is connected with an input end of the signal processing circuit; 
 the signal processing circuit comprises a first capacitor, a second capacitor, a Faraday shield and a step-up transformer; 
 the Faraday shield is fixedly arranged between a primary winding and a secondary winding of the step-up transformer; 
 a center tap is arranged at the primary winding of the step-up transformer, and the center tap is grounded; and 
 a first end of the primary winding is in series connection with the first capacitor, and a second end of the primary winding is in series connection with the second capacitor; 
 wherein, the magnetic probe body comprises a probe head, a first coaxial cable, a second coaxial cable and a quartz tube; 
 the first coaxial cable and the second coaxial cable are arranged in parallel, the first coaxial cable and the second coaxial cable are exteriorly and integrally coated with an aluminum foil, and the first coaxial cable and the second coaxial cable, which are coated with the aluminum foil, are inserted to and fixed in an interior of the quartz tube; 
 the probe head is formed by a two-turn coil; 
 a first end of the probe head is connected with a first end of the first coaxial cable, and a second end of the probe head is connected with a first end of the second coaxial cable; a second end of the first coaxial cable is connected with the first end of the primary winding of the step-up transformer; and, 
 a second end of the second coaxial cable is connected with the second end of the primary winding of the step-up transformer. 
 
     
     
       2. The magnetic probe device according to  claim 1 , wherein the magnetic probe device further comprises an oscilloscope, an output end of the signal processing circuit is connected with the oscilloscope, and the oscilloscope is used for displaying an output voltage of the signal processing circuit. 
     
     
       3. The magnetic probe device according to  claim 1 , wherein a diameter of the coil is 10 mm, and a material of the coil is an enameled wire or a tungsten wire. 
     
     
       4. The magnetic probe device according to  claim 1 , wherein the characteristic impedance of the first coaxial cable is 50 ohms, and the characteristic impedance of the second coaxial cable is 50 ohms. 
     
     
       5. The magnetic probe device according to  claim 1 , wherein a magnetic probe body further comprises a first subminiature version (SMA) radio frequency (RF) connector and a second SMA RF connector; and the second end of the first coaxial cable is connected with the first end of the primary winding through the first SMA RF connector, and the second end of the second coaxial cable is connected with the second end of the primary winding through the second SMA RF connector. 
     
     
       6. The magnetic probe device according to  claim 1 , wherein the first capacitor and the second capacitor are variable capacitors. 
     
     
       7. The magnetic probe device according to  claim 1 , wherein a capacitance value of the first capacitor is 155 pF, and the capacitance value of the second capacitor is 155 pF.